Report: Less than 1% of Water in LA is Recycled
By setting bar low, SoCal agencies may meet water saving goals -- but region remains dependent on imported water
USC Media Relations, LatinoLA Contributor
Urban water scarcity is an ongoing reality in arid Southern California, and the region remains dependent on imported water, reveals a new two-year analysis of water conservation management in Southern California.
Published on LatinoLA: March 4, 2013
Led by researchers at USC, the report, "Water Supply Scarcity in Southern California," examines water management strategies that were implemented in 2009 as part of legislation to encourage conservation and reduce dependence on single sources of water.
The report provides a critical assessment of continued water supply vulnerabilities, whether the region is on-track to meet conservation goals, and the most cost-efficient strategies for water conservation in the future.
"We still have significant challenges to overcome in water management with political fragmentation and skepticism," said Hilda Blanco, lead investigator on the report, and research professor at the USC Price School of Public Policy. "By mid-century, high warming estimates could lead to chaos for local water providers, and even under average warming scenarios water agencies will have to make deep adjustments in their plans or face less water for everyone."
Published by the USC Center for Sustainable Cities, the report shows that Southern California needs imported water to quench its thirst. Of the water districts analyzed in the report -- the Los Angeles Department of Water and Power (LADWP), the Cucamonga Valley Water District and the Huntington Beach Utilities Department -- all still lean on imported water from the Sacramento-San Joaquin River Delta and the Colorado River as a main water source.
For LADWP, 52% of water is imported, 36% comes from the LA Aqueduct, 11% comes from groundwater and less than 1% is recycled, the report found. The largest available current source of groundwater for LADWP is the San Fernando Basin, which is heavily polluted and a designated EPA Superfund Clean-up Site.
In contrast, Huntington Beach, which used the least imported water of the Southern California regions studied, imports 32% of its water and gets 68% from local groundwater.
However, the researchers found that LADWP has the most coherent plan in place to address water shortages in the future, including clean-up of the San Fernando Basin, tiered pricing for water use, and municipal programs to encourage the adoption of water-saving appliances, such as rebates or mandates for new construction. LADWP also plans to spend more then $500 million over the next decade to expand the infrastructure for recycled water and to decrease the proportion of imported water to 24%.
"By setting low targets, many agencies have ensured that they will have little trouble meeting water conservation goals," Blanco said, noting that Southern California agencies were allowed to set their own baselines for the state's goal of 20% reduction in per capita water use by 2020. "The management of groundwater is so fragmented among multiple basins and water rights holders that the region lacks the ability to plan realistically for the future. The state needs a comprehensive strategy to manage this critical resource."
Among the study's other key findings are:
ÔÇó For LADWP, imported water is the most expensive water resource in terms of energy used and greenhouse gases emitted. Imported water from Northern California and elsewhere is 12-15 times more energy intensive than water from the L.A. Aqueduct (which is conveyed by gravity), and causes 8-10 times the emission of greenhouse gases.
ÔÇó 70% of LADWP demand for water comes from residential customers: 38% from single-family homes and 32% from multi-family residences. Multi-family developments tend to use less water per capita than single-family homes.
In Cucamonga Valley Water District, 22% of water demand is for landscaping. More than half of water demand (about 55% of total water usage) is for single family homes.
In Huntington Beach, declining population has been mirrored by decline in water demand. Since 1999, per capita water use has constantly declined.
Water conservation strategies vary in cost-effectiveness, and what works in one district might be a wash in another. For example, the report shows the replacement of turf with synthetic turf is borderline cost-effective in the Cucamonga Valley Water District, with a benefit-cost ratio of 0.96. In contrast, outdoor weather-based irrigation controllers have a benefit-cost ratio of over 11, meaning the region gets back $11 in savings for every dollar spent.
The report makes several recommendations, including investment in technological innovations for water irrigation, continuing research on climate change impacts on water resources, and a statewide coordinated strategy for water management.
This research was funded by the Haynes Foundation. Marina Alberti of the University of Washington, Joshua Newell of the University of Michigan and Lowell Stott of USC contributed to the report.
For a full copy of the report, visit the USC Center for Sustainable Cities website at http://sustainablecities.usc.edu/research/publications.html. Professor Hilda Blanco is interim director of the USC Center for Sustainable Cities.